public class ZY1 {
    public static void main(String[] args) {
        //P76编程题的第二小题
        /*int[] a={25,24,12,76,101,96,28};
        for (int i = 1; i <a.length; i++) {
            for (int j = 0; j <a.length-i; j++) {
                if(a[j]>a[j+1]){
                    int b =a[j];
                    a[j]=a[j+1];
                    a[j+1]=b;
                }
            }

        }
        for (int i = 0; i < a.length; i++) {
            if(i==a.length-1){
                System.out.println(a[i]);
                break;
            }
            System.out.print(a[i]+",");
        }*/
        //P76页编程题的第一小题
        int n=0;
        for (int i = 1; i < 99; i++) {
            if(i%2!=0){
                n+=i;
            }
        }
        System.out.println(n);
    }
}
